Fabrication of many articles, including flexible electronic or optical components, involves registration between layers of material deposited or formed on an elongated substrate or web. The formation of the material layers on the web may occur in a continuous process or a step and repeat process involving multiple steps. For example, patterns of material may be deposited in layers on an elongated substrate, such as a web, through multiple deposition steps to form layered electronic or optical devices. Some articles require precise registration of features that are applied on one or both sides of the substrate.
To achieve accurate registration between the layers, lateral (crossweb) positioning and longitudinal (downweb) positioning must be maintained as the substrate moves through multiple manufacturing steps. Maintaining registration between layers formed on the substrate becomes more complex when the substrate is flexible or stretchable. Some articles are made in multiple steps during which materials or processes are sequentially applied to the substrate, requiring precise position registration for each of the process steps.
Fiducials are orientation features of a substrate that can be used to determine the substrate position as the substrate moves, along with the articles being formed thereon, through various fabrication steps. It is desirable to increase the resolution obtainable from the substrate fiducials to enhance substrate position sensing. There is a need for enhanced methods and systems to make fiducials on a substrate which simplify production, reduce costs and/or increase the resolution of substrate position sensing. The present invention fulfills these and other needs, and offers other advantages over the prior art.